While Beta catenin was originally identified as a component of multimolecular complex that interacts with the intracellular domain of cadherin family adhesion molecules, it has recently become clear that Beta-catenin plays a role in inductive signal transduction pathways that lead to normal axis formation in Xenopus laevis. The research proposed here focuses on the identification and characterization of genes whose expression is rapidly altered in response to the Beta-catenin signaling pathway. Experimentally, isolation of b-catenin-responsive genes will be carried out using the differential display technique on RNA derived from Beta-catenin vs. control injected Xenopus embryos. Further characterization of isolated sequences will be carried out by analysis of the temporal and spatial regulation of differentially expressed products, the cloning and sequencing of cDNAs encoding these products, and an assessment of the effects of overexpression of these Beta-catenin- responsive gene products. This research project will provide valuable insight into the molecular details of a centrally important signaling pathway in early vertebrate development